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Opened Gaggia boiler - how to deal with corrosion? Incl photos...

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  • Opened Gaggia boiler - how to deal with corrosion? Incl photos...

    ** Any advice on the following issue would be much appreciated. Please read my question following the photos and provide any thoughts **

    Some of you may have seen my other posts about the bargain second hand Gaggia Coffee Deluxe that I bought from a fellow CSer.

    Its around 3 years old but hasnt been used much, and when I ran water through it some very fine white powder came out. After reading some threads and asking some questions I decided that it was corrosion and I needed to take the boiler apart.

    With some Google action and some good advice from Kaanage I disassembled the boiler, and what I found was truly disturbing:





    So I got to work cleaning out the crap and scrubbing away the corrosion.  I got good results with the bottom section of the boiler, which I believe is made of brass rather than aluminium:



    However, I wasnt able to get the top section of the boiler as clean.  I used a scotch brite pad (non-metallic) and switched to some steel wool when I wasnt getting far with the original pad.

    The results of my attempts at cleaning the top half are in the photo below.  As you can see, there is still corrosion on the inside of the boiler (although its not a thick layer).

    What I need advice on is whether this is acceptable in terms of putting the machine back together and starting to make coffee, or whether I need to take some more drastic action to completely remove all traces of corrosion.

    If you think I can/need to deal more thoroughly with the corrosion, please let me know how.




  • #2
    Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

    I wouldnt put it back as is.

    You should be able to soak it in a cleaning solution to get rid of the rest.
    What you have remaining looks like it will soon flake off if not taken care of now.

    Im no expert in these things but someone should be along soon.

    To help them...please clarify what metal the top part of the boiler is made of.
    Brass or aluminium?

    Youll need the correct solution for each metal.

    Comment


    • #3
      Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

      Thanks for the input.

      I should note that what you can see on the left wall in the bottom two pictures is pitting, not flakes of corrosion. The lighting is a bit deceptive.

      Anyone else have comments re. how to remove the remaining corrosion?

      Comment


      • #4
        Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

        I would try and soak the parts in a solution of cleaning product and water designed for aluminum thermoblock or boiler machines. Sunbeam have a cleaning tablet which I use in my em6910, but the damage may be to far gone.

        Comment


        • #5
          Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

          you will be need ing some new seals for that as well, it is not advised to reuse seals once disturbed.

          i bet there are alot of boilers out there looking like that but no one would know until they pull it apart.

          Comment


          • #6
            Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

            It makes absolutely no sense and basic engineering says you should avoid brass/aluminium combinations because of their high electrochemical differences which will inevitably lead to galvanic corrosion. Poor design if Gaggia did actually use two significantly different electrochemical metals

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            • #7
              Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

              Originally posted by 7B595F4443495F2C0 link=1242478640/5#5 date=1242567018
              Poor design if Gaggia did actually use two significantly different electrochemical metals
              ...or good design if they wanted their boilers to have a finite life?

              Great photos, but yes, disturbing.

              I wonder if it would be worth talking to an electroplater to see if there is a coating they would recommend? There should be a food grade hardcoat anodising that would be safe to use and might stop the problem... or maybe thermoplastic powdercoating (which I know can be food grade)

              Comment


              • #8
                Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

                Originally posted by 373B323231310B273A3B36540 link=1242478640/4#4 date=1242517472
                you will be need ing some new seals for that as well, it is not advised to reuse seals once disturbed.
                No, Ive dealt with a few like this and you dont need any new seals at all. You probably need to clean up the lower o-ring with a brillo pad and at the worst, also clean up the base of the boiler a bit (place glass paper on a very flat surface and rub down the boiler with a figure-8 pattern).

                Originally posted by 373B323231310B273A3B36540 link=1242478640/4#4 date=1242517472
                i bet there are alot of boilers out there looking like that but no one would know until they pull it apart.
                True but theyre no/\/t basket cases as everyone here tends to presume.

                Yes, you can investigate electroplating with chrome but its expensive and tends to flake if the surface is not perfectly cleaned with an acid bath. Check with a motorcycle engine rebuilder if you really want to go down this route as it is expensive - 2 stroke motocross and grand prix engines sometuimes use this sort of plating (nikasil is not suitable as is is a surface hardening process that depends on the alumnium having a high silica content which I highly doubt would be used by Gaggia). I doubt powder coating would last given the themal cycling it would be subjected to.

                Personally, Id get a bit of glass paper, wrap it over a longish screw driver and use this to clean out the boiler innards and clean up the base with some more glass paper and then put it all together and use it.

                That is particularly bad for the age of the machine but it will work just fine when cleaned up. I have older machines that got used a lot without any visible corrosion (just the flaky white scaling).

                Yes, it is poor engineering given then built in galvanic corrosion but the machines will work for long periods and are easy to fix and the boilers are cheap if they are that far gone (this one is no where near being a replacement candidate).

                PM SJM if you need any more advice on the longevity of Gaggias.

                Comment


                • #9
                  Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

                  Originally posted by 565C5C535C5A583D0 link=1242478640/7#7 date=1242604894
                  Personally, Id get a bit of glass paper, wrap it over a longish screw driver and use this to clean out the boiler innards and clean up the base with some more glass paper and then put it all together and use it.
                  Thanks everyone for the thoughts.  I actually decided to do what Kaanage recommended on Sunday after discussing with my dad.  Got some very fine sandpaper and it took all the corrosion off very easily.

                  Dad expressed some concern about a bit of pitting on the mating surface of the aluminium half of the boiler, because he thought it could lead to a breach of the seal with the bottom half.  He suggested that I fill in the pits (there were only 2) with Araldite and then use a razor to trim the excess so that it was perfectly smooth.

                  I did this and it ended up looking pretty good - should have taken another photo before putting it back together but I forgot.  Anyway after reassembling, I ran a tank of water through the machine - no nasty corrosion and a better water flow too - then make some coffee.  It was great.

                  I pulled another couple of shots today and checked inside the machine - no sign of any leakage or any other problems.  While only time will tell whether my repairs have compromised the integrity of the boiler, I am pretty confident that they havent and Ill get great coffee out of it for quite some time (given the excellent condition overall).

                  I also learned heaps about the workings of the machine and found it very satisfying to take everything apart, fix a problem and successfully put everything together again.  I might write a separate thread about how to dismantle and clean a Gaggia boiler using the photos that Ive pasted here, cos its easy and worthwhile.

                  Thanks all
                  MF

                  Comment


                  • #10
                    Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

                    Originally posted by 504F5B484F5452533D0 link=1242478640/8#8 date=1242608068
                    Dad expressed some concern about a bit of pitting on the mating surface of the aluminium half of the boiler, because he thought it could lead to a breach of the seal with the bottom half.He suggested that I fill in the pits (there were only 2) with Araldite and then use a razor to trim the excess so that it was perfectly smooth.
                    Will araldite remain inert in the boiler? Id be a bit worried that it might leach something (flavour or other toxic chemicals) into the boiler water, particularly it will be constantly exposed to water (and often boiling water). I dont know the answer to this - it was just the first thing that came to mind when you mentioned youd used araldite.

                    Comment


                    • #11
                      Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

                      Assuming it behaves like most epoxies it should be pretty inert once cured. Much more so than say poly resin used in surfboard. But I still dont know if id want it getting into the water.
                      Given you said it is only on the mating surfaces and not inside the boiler (i.e. in contact with the water) it may not be an issue.

                      But Id be wondering if it wont just liquify when the boiler gets hot. Epoxy gets gummy and soft at elevated temps.

                      All up to you in the end.

                      Comment


                      • #12
                        Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

                        I would suggest that many glues will not stand up to the job..

                        There are some great metal fillers that harden and do allow machining etc after they have cured... As always... The issue is, if they are suitable and do not taint the water...

                        Comment


                        • #13
                          Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

                          JB Weld is an metallic 2 part epoxy that is rated to 300d
                          I use it in slot car motors that regularly run to 120d
                          It can be sanded & filed etc.
                          You can get this at K-mart

                          Comment


                          • #14
                            Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

                            I personally wouldnt go down the glue route especially if it has the chance to come in to contact with the brew water. Try sanding down the pitted aluminium side, then pop in your new boiler gasket. Requires a bit of manual labour, but it will work.

                            Comment


                            • #15
                              Re: Opened Gaggia boiler - how to deal with corrosion? Incl photos...

                              My brother and dad are both engineers and they agreed that Araldite can stand extreme temperatures - my brother has used it inside his motorbike engine which gets much hotter than an espresso machine boiler (he estimated a couple of hundred degrees).

                              Im not too concerned that it will taint the water because it shouldnt even come into contact with it.

                              Comment

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